1. Field of the Invention
This invention relates generally to catheters and, more particularly, to catheters using electroactive or electromechanical polymer actuators to provide articulation.
2. Discussion of the Related Art
Numerous medical procedures (e.g., angioplasty, stenting, cardiac ablation, and vascular diagnostics) use catheters. It is difficult, however, to steer a catheter's tip to a desired location in the body effectively through the vasculature. Typically, a procedure begins when a physician inserts a distal portion of a guide wire into a patient's vasculature system. Once the distal portion of the catheter—which follows the distal portion of the guide wire—enters into the vasculature, the physician can no longer manipulate the distal portion of the guide wire directly. Thereafter, the physician must advance the guide wire through the vasculature by manipulating (e.g., pulling, pushing, and twisting motions) from the proximal end of the catheter. The typical guide wire relies on its flexibility to avoid causing trauma to the surrounding tissues. This flexibility makes steering the guide wire even more difficult.
Another drawback in conventional catheter use is that many procedures require multiple catheters. This is because, to reach an intended location within the vasculature, multiple catheter tips with different preformed shapes and different degrees of bending may be required. Consequently, the hospital must maintain a large inventory of catheters because it is difficult to predict in advance which catheters are required. The repeated catheter extraction and insertion may also increase the risks of infections and trauma to the patient.
U.S. patent application Ser. No. 13/734,866, entitled “Steerable Medical Guide Wire Device,” filed on Jan. 4, 2013, and U.S. patent application Ser. No. 11/898,475, entitled “Micro-steerable Catheter,” filed on Sep. 17, 2007 disclose catheters and materials for various medical applications. The disclosures of these copending U.S. patent applications are hereby incorporated by reference in their entireties.